Topic of the Lecture: Methods of examination (evaluation) of auditory and vestibular systems

1 Definition

 Otolaryngology is the branch of medicine that specializes in morphology, physiology and pathology of , nose, upper respiratory system and nearby regions.

2 Term - otorhinolaryngology

 Otos - ear  Rhinos - nose Greek words  Laryngos - larynx/throat  Logos -study

abbreviated– ORL or LOR

3 Peripheral region

Sound conduction system Sound perception system 1. Outer ear; 2. Middle ear; 1. The organ of Corti (or spiral organ) 3.Peri- and endolymphal cavities; 4.Basilar membrane; * 5. Tectorial membrane.

*- inner ear structures.

4 Normal properties:

1. Frequency Range of Human Hearing- from 16 to 20 thsd. Hz. By bone conduction human perceives ultrasound up to 224 thsd. Hz. Normal speech frequency range– 500 – 2000 Hz 2.Unequal sensitivity to various frequencies. 3. Ototopics - capacity of localizing the source of a sound.

5 The human auditory system is sensitive to sounds in terms of: - frequency (Hz); - magnitude(Db). 130 Db – highest intensity sound human is able to perceive. 30 Db – low intensity sound. 60 Db – lector’s speech. Absence of tympanic membrane and ear – on 25-30 Db. Auditory discomfort - 80-100 Db. Rock music: - 106-110 Db in the middle of a hall;

- 120 Db near stage. 6

Auditory system according to Pavlov I.P. is divided as follows:

1. Peripheral region.

2. Transmitting pathway (Central auditory system).

3. Cortical region (primary auditory cortex).

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Anatomical structures of neuronal processing :

Spiral ganglion- І neuron

Medulla oblongata (nucleus ventralis, nucleus dorsalis) - ІІ neuron; partial decussating

Superior olivary complex- ІІІ neuron

Inferior colliculi, Medial Geniculate Nucleus- ІV neuron

Temporal lobe (superior temporal gyrus)

8 Bone conduction

1 . Inertial type (low-pitched sounds).

2. Compressional type (high-pitched sounds).

9 Hearing Testing

І group – Speech test. ІІ group- tuning fork tests.  Schwabach test.  .  .  Bing test.  Federici test.  Gelle test. ІІІ group –electrophysiological or electroacoustic tests. • Subjective methods • Objective methods VІ group – using conditioned and unconditioned reflexes: • Unconditioned – auropalpebral and auropupillary reflexes • Conditioned - Conditioned Play . 10

ІІІ group – electrophysiological or electroacoustic tests. Subjective methods

- Pure tone threshold audiometry; - above-threshold audiometry • Si-Si test - small increment sensitivity index test. • differential threshold test (Lüscher-Test). - Speech audiometry; - Sesitivity to ultrasound; - Hearing testing in wide frequency range.

11 ІІІ group – electrophysiological or electroacoustic methods Objective methods

- Registration of brainstem and cortical response to sound (computer audiometry/auditory brainstem response (ABR)ка аии); - Electrocochleography (ECochG); - Immittance Audiometry; - Evoked Otoacoustic Emissions.

12 Audiometry

Normal

13 Audiometry

Conductive hearing loss

14 Audiometry

Perceptive hearing loss

15 Audiometry

Combined hearing loss 16 Immittance Audiometry

thresholds  Acoustic Reflex Decay  Determination of auditory tube passage capability (function) with perforated and non-perforated tympanic membrane

17 Immittance Audiometry – objective hearing test method Tympanometry – 6 tympanogram types (Jerger, 1970)

type a (normal) type Аs () type С (disfunction of auditory tube)

type secretory otitis media, В ( type Аd (ossicle chain type D (adhesive otitis) perforation of tympanic membrane) disfunction) 18

Methods of examination of vestibular system (vestibulometry)

19 Functions of vestibular system

Otolithic organs the semicircular canal system

• linear acceleration (on horizontal and  Angular vertical plane) acceleration

• gravity

20 Aim of vestibulometry

 Determination of central and peripheral vestibular syndromes  Determination of hypo- or hyperreflexia of labyrinth

21 Group of tests

1) Spontaneous vestibular disfunctions 2) Experimental tests (tests with provocative measures )

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Spontaneous Vestibular Disfunctions

1. Dizziness.

2. Spontaneous past-pointing tests (outstretched hands test, pointing test, Fukuda's vertical writing test– number 30, normally deviation no more then 100).

3. Balance system evaluation (Romberg pose; ефаография (Kephalography?) – 60 dots in 60 seconds, Stabilography – evaluation of body's center of gravity, walk test).

4.Evaluation of reaction: 1) Spontaneous nystagmus; 2) Positional nystagmus; 3) Optokinetic nystagmus; 4) Pressure nystagmus.

23 Electronistagmography

 Registration of potential difference between retina and iris tunic eyeball moving

24 Experimental tests

 Caloric stimulation

 Rotation tests

25 Caloric test

26 Caloric test

27 Rotation tests

28 Posturography

29 Vestibulometry in professional selection

 Otolithic reaction (off vertical axis testing).  Multiple repetition of OR (10 tests on right side and as many on the left with 2-3 min. pause)  Coriolis Acceleration Tolerance test (test of continuous accumulation of coriolis acceleration in modification of Markarian S.S.)

30 Otolithic reaction (off vertical axis testing)

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Vestibulometry in professional selection Otolithic reaction (off vertical axis testing)(Voyachek V.G.) somatic reactions vegetative reactions 0 – reactions are absent 0 – reactions are absent 1 – slight deviations of the body 1 –(subjective feeling of ) 2 –strong deviations of the nausea body 2 –paleness or redness of face, 3 – fall out changes in heart and breath rate (subject (patient) can not hold himself in the chair) 3 – nausea and vomit

32 Accumulation test ( 4 support PL swing)

33 Vestibulometry in professional (occupational/career) selection Khilov K.L. (provocative factors/irritants) cummulation test

 0 degree- after 15 minutes of swinging vegetative reactions are absent;  І degree- after 15 minutes of swinging nausea and vomit occurred;  ІІ degree- after 5-15 minutes of swinging nausea and vomit occurred;  ІІІ degree- in first 5 minutes of swinging nausea and vomit occurred.

34 Coriolis Acceleration Tolerance

Coriolis Acceleration arises as a result of motion of a particle relative to a rotating system (overlaying of either perpendicular forces)

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